Step 1Heat the oven to 400 degrees.
Step 2In a blender or food processor, combine one-fourth cup sugar, the eggs, cream, milk and vanilla and blend until smooth. Sift the flour over the mixture and pulse just to mix. Set the batter aside to stand 10 minutes.
Step 3While the batter is resting, peel the pears, cut them in half lengthwise and remove the core and the stem line with a spoon (a grapefruit spoon works best). Cut each half in crosswise slices one-fourth to one-half-inch thick; do not separate the slices.
Step 4Arrange the sliced pear halves in a 9-inch pie plate with the stem ends pointing toward the center and a little space between each. Depending on the size of the pears, you may be able to use only 5 of the 6 halves. Pour the batter over the top and sprinkle with the pistachios. Depending on how sweet the pears are, sprinkle an additional 1 to 2 tablespoons sugar over the pears that peek out from under the batter.
Step 5Place on a cookie sheet to catch any spills. Bake until the clafouti is puffed and brown in the center, about 40 to 45 minutes. Cool slightly before serving.